Electrically heated tool



Aug. 31, 1948. 2. KALFEN I 2,448,18

ELECTRICALLY HEATED TOOL Filed July 5, 1946 Patented Aug. 31, 1948UNITED STATES PATENT OFFICE ELECTRICALLY HEATED TOOL Zoltan Kalfen,Chicago, 111.

Application July 3, 1946, Serial No. 681,185

7 Claims. 1

This invention relates to electrically heated tools such as solderingirons and more particularly to tips used in such electric solderingirons.

It is the known object of all soldering irons to bring the solderingtips to required temperatures as quickly as possible and the greatmajority of electric soldering irons now in use are designed andconstructed to achieve this purpose. Generally, the heating element isenclosed in a casing which is adapted to snugly receive the tip so thatthe heat is directly transmitted to the soldering member.

The tips being of high thermal conductivity, their co-efllcient ofexpansion is great and because temperature extremes cause rapiddeterioration, frequent tip replacements are necessary.

This combination of circumstances often results in a, condition where aworn tip, because of expansion in the sleeve cannot be removed from theiron without reaming or boring which results in impairment ordestruction of the heating element necessitating not only replacement ofan expensive part, but also delays the use of the soldering iron itselffor indefinite periods.

It is an important object of the present invention to obviate the abovediificulties by providing a soldering tip which can be used with anyconventionl soldering iron and which may easily be removed when desired.

It is a further object or the present invention to provide a solderingtip of high thermal conductivity but wherein the expansion in the sleeveis controlled to permit easy withdrawal.

Another object of the present invention is to provide a soldering tipwhich will heat faster than the soldering tips now in use withoutbecoming so tightly wedged in the sleeve as to require reaming orboring.

These and numerous other objects and advantages will be apparentthroughout the progress of the following specifications.

The accompanying drawing illustrates a se lected embodiment of theinvention and the views therein are as follows:

Fig. 1 is a plan view partly in section showing the soldering tip in theiron ready for use.

Fig. 2 is an anterior end view of the soldering tip showing the channeltherein.

Fig. 3 is a perspective view of a. soldering tip embodying the presentinvention.

Fig. 4 is a, perspective view of another form of soldering tip embodyingthe present invention.

The soldering tip shown herein for the purpose of illustrating thepresent invention comprises a rod ID of any desired material, generallyof cold rolled copper, having the tapered posterior end i I and itsanterior end sheared at an angle of substantially degrees shown at l2.

Extending along the major portion of the longitudinal section and beyondthe anterior end of said rod is the channel l3 preferably 1 of an inchWide and. having a depth slightly greater than the transverse centroidof area of said rod as clearly shown at l4 in Figs. 2 and 3. The saidchannel l3 may be made by any well known method.

Shown in Fig. 1 is the conventional electric soldering iron l5, havingthe usual electrical connection I6, the head I! in which is enclosed theheating element l8 and which also provides the sleeve l9 to receive thesoldering tip Hi. It is not deemed necessary to explain the solderingiron as its construction is well known.

Some forms of conventional soldering irons are constructed to secure thetip to the head by screw threads and in Fig. 4 is shown a soldering tipembodying the present invention having threads 20 at the anterior endfor use in such irons.

It has been found to be of utmost importance that the channel I3 be ofsufllcient length so as to extend through and slightly beyond the headI! of the soldering iron as clearly shown in Fig. 1 and that the depthof the channel be slightly greater than the transverse centroid of areaof the tip. A channel width of of an inch has been found to be mostsatisfactory.

The present invention provides a soldering tip which is extremelysimple, inexpensive to manufacture, yet which heats faster than the tipsof the prior art. Because of its construction, expansion will not causewedging in the sleeve of the head and it is easily removable withoutinjuring or destroying the heating element.

Changes may be made in form or construction without departing from thespirit of the invention or sacrificing any of its advantages and theright is hereby reserved to make all changes as fairly fall within thescope of the following claims.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is as follows:

1. A soldering tip of high thermal conductivity and comprising anelongated fabricated element, 9. slot extending along a portion of the1ongitudinal length of said element and beyond the anterior end thereof,said slot being directed inwardly toward the center of said element andextending to a depth slightly beyond said center of said element.

2. A soldering tip of high thermal conductivity comprising an elongatedrod fabricated and tapered at the posterior end, a channel extendingalong a portion of the longitudinal section of said rod and beyond theanterior end thereof said channel being directed inwardly toward thecenter of said rod and extending to a depth slightly beyond such center.

3. A thermal conducting element comprising an elongated metallic rod, achannel extending along the greater portion of the longitudinal'sectionof said rod beyond its anterior end, said channel being directedinwardly toward the center of said rod and bein undercut to a depthslightly beyond said center of said rod, an anterior transverse sectionmachined at an angle of ninety degrees to said longitudinal section anda posterior section tapered and fabricated to facilitate soldering.

4. A thermal conducting element comprising an elongated metallic rod,said rod being tapered and fabricated at the posterior end for solderapplication a channel extending along'a portion of'the longitudinalsection of said rod substantially two thirds the length of said rod-fromthe anterior end, said channel extending inwardly toward the center ofsaid rod and to a depth. slightly beyond said center.

5. An elongated metallic soldering tip comprising a fabricatedlongitudinal section, a posteriorsection fabricated to facilitatesoldering, an anterior section sheared atv an angle of approximatelyninety degrees, a channel substantially T of'aninch in width, extendingalong the longitudinal section of said'rod beyond the anterior endthereof; said channel being of a length substantially two-thirds of th-length of said rod from its anterior end and being directed inwardlytoward the center of said rod and to a depth slightly beyond saidcenter.

6. In combination, an electric soldering iron having a heating elementwithin an outer casing adapted to receive a soldering tip, an elongatedmetallic rod shaped at the posterior end 5 and sheared at an angle ofninety degrees at the anterior end, a channel extending along thelongitudinal section of said rod beyond the anterior end thereof, saidchannel being of a length greater than the length of the portion of therod enclosed in the said heating element and said channel being directedinwardly toward the center of said rod and being undercut to a depthslightly beyond the center of said rod.

'7. In combination, an electric soldering iron having a heating elementwithin an outer casing adapted to receive a soldering tip, a solderingtip of highthermal conductivity capable of fitting in said heatingelement, said soldering tip being tapered and fabricated at theposterior end,

a channel substantially 1 g of an inch in width extending-along themajor portion vof. the longitudinal section ofsaid solderin tipbeyond-the anterior end thereof,.said channel having alength greaterthan the length of the portion enclosed to a depth extending slightlybeyond said center of said soldering tip centroid of area and alength,greater than the length of the portion enclosed.

in said heating element.

ZOLTAN KALFEN.

REFERENCES- CITED The'following references are-of record in the fileof'this patent:

UNITED STATES PATENTS in said heating element and being directediinWardlytoward the center of said soldering tip.

